Abstract
We measured the contents of calcium, potassium, magnesium, manganese and pectin in the seed coat and cotyledons of soybean cultivars with different frequencies of seed coat cracking cultivated in different regions in Japan. The calcium content of cotyledons in the soybean cultivar ‘Sachiyutaka’, which had a high frequency of seed coat cracking, was lower than those in the other cultivars. However, there was no significant difference in calcium contents of cotyledons between the cracked seeds and intact seeds in any cultivar. The calcium content of seed coat, revealed no significant difference between the cultivars or between the cracked seeds and intact seeds. The contents of potassium, magnesium and manganese not only of seed coats but also of cotyledons, showed no significant difference among the cultivars or between the cracked seeds and intact seeds. The ratios of potassium to calcium content in cotyledons of were nearly the same in cracked seeds and intact seeds in all cultivars. However, the ratio in cracked seed coat was lower than that in intact seed coat in the plants cultivated under the same conditions, although there was no varietal difference in the ratio. These results, suggested that the balance between potassium content and calcium content plays an important role in cracking of seed coat. On the other hand, the concentration and the form of pectin were not correlated with the cracking of seed coat.
